A 2-V 2-GHz BJT variable frequency oscillator

Abstract

A new LC-tuned negative-resistance variable-frequency oscillator (VFO) is described. Frequency tuning is accomplished by using a variable-impedance converter (VIC) to simulate the varactor function, A negative-impedance converter provides the necessary negative resistance for oscillation and also functions as the voltage level shifters for the VIC. A low-voltage translinear circuit is used to linearize the tuning characteristic of the VFO. Implemented in a 0.8 mu m 12 GHz f(T) BiCMOS technology, the VFO has a tuning range from 1.55 to 2.02 GHz, while consuming 15 mA from a -2 V supply.